internal static string GetYamlCompatibleString()

in src/Microsoft.OpenApi/Writers/SpecialCharacterStringExtensions.cs [107:200]
69 lines of code
12 McCabe index (conditional complexity)

        internal static string GetYamlCompatibleString(this string input)
        {
            // If string is an empty string, wrap it in quote to ensure it is not recognized as null.
            if (input == "")
            {
                return "''";
            }

            // If string is the word null, wrap it in quote to ensure it is not recognized as empty scalar null.
            if (input == "null")
            {
                return "'null'";
            }

            // If string is the letter ~, wrap it in quote to ensure it is not recognized as empty scalar null.
            if (input == "~")
            {
                return "'~'";
            }

            // If string includes a control character, wrapping in double quote is required.
            if (input.Any(c => _yamlControlCharacters.Contains(c)))
            {
                // Replace the backslash first, so that the new backslashes created by other Replaces are not duplicated.
                input = input.Replace("\\", "\\\\");

                // Escape the double quotes.
                input = input.Replace("\"", "\\\"");

                // Escape all the control characters.
                input = input.Replace("\0", "\\0");
                input = input.Replace("\x01", "\\x01");
                input = input.Replace("\x02", "\\x02");
                input = input.Replace("\x03", "\\x03");
                input = input.Replace("\x04", "\\x04");
                input = input.Replace("\x05", "\\x05");
                input = input.Replace("\x06", "\\x06");
                input = input.Replace("\a", "\\a");
                input = input.Replace("\b", "\\b");
                input = input.Replace("\t", "\\t");
                input = input.Replace("\n", "\\n");
                input = input.Replace("\v", "\\v");
                input = input.Replace("\f", "\\f");
                input = input.Replace("\r", "\\r");
                input = input.Replace("\x0e", "\\x0e");
                input = input.Replace("\x0f", "\\x0f");
                input = input.Replace("\x10", "\\x10");
                input = input.Replace("\x11", "\\x11");
                input = input.Replace("\x12", "\\x12");
                input = input.Replace("\x13", "\\x13");
                input = input.Replace("\x14", "\\x14");
                input = input.Replace("\x15", "\\x15");
                input = input.Replace("\x16", "\\x16");
                input = input.Replace("\x17", "\\x17");
                input = input.Replace("\x18", "\\x18");
                input = input.Replace("\x19", "\\x19");
                input = input.Replace("\x1a", "\\x1a");
                input = input.Replace("\x1b", "\\x1b");
                input = input.Replace("\x1c", "\\x1c");
                input = input.Replace("\x1d", "\\x1d");
                input = input.Replace("\x1e", "\\x1e");
                input = input.Replace("\x1f", "\\x1f");

                return $"\"{input}\"";
            }

            // If string 
            // 1) includes a character forbidden in plain string,
            // 2) starts with an indicator, OR 
            // 3) has trailing/leading white spaces,
            // wrap the string in single quote.
            // http://www.yaml.org/spec/1.2/spec.html#style/flow/plain
            if (_yamlPlainStringForbiddenCombinations.Any(fc => input.Contains(fc)) ||
                _yamlIndicators.Any(i => input.StartsWith(i.ToString())) ||
                _yamlPlainStringForbiddenTerminals.Any(i => input.EndsWith(i.ToString())) ||
                input.Trim() != input)
            {
                // Escape single quotes with two single quotes.
                input = input.Replace("'", "''");

                return $"'{input}'";
            }

            // If string can be mistaken as a number, a boolean, or a timestamp,
            // wrap it in quote to indicate that this is indeed a string, not a number, a boolean, or a timestamp
            if (decimal.TryParse(input, NumberStyles.Float, CultureInfo.InvariantCulture, out var _) ||
                bool.TryParse(input, out var _) ||
                DateTime.TryParse(input, out var _))
            {
                return $"'{input}'";
            }

            return input;
        }